Nanosized Titanium Carbide MXene‐Supported Bimetallic Au@Ag Nanocubes as a Highly Efficient Catalyst for Nitroaromatics Reduction

Abstract In this work, a novel nanosized Ti ₃ C ₂ MXene‐supported Au@Ag nanocube catalyst synthesized via a three‐step process is reported. The Au@Ag nanocubes are selected for their synergistic properties, combining the electron‐donating ability of Ag with the catalytic stability of Au, thereby enhancing electron transfer and accelerating reduction reactions. Nanosized Ti ₃ C ₂ MXene served as a support owing to its high surface area, conductivity, and abundant active sites, promoting strong metal‐support interaction and uniform nanocube dispersion. The catalysts are applied for rapid aqueous‐phase reduction of nitroaromatics, including 4‐nitrophenol (4‐NP), 4‐nitroaniline (4‐NA), and 4‐nitrobenzaldehyde (4‐NB), using NaBH ₄ at room temperature. The Au@Ag nanocubes (71.7 ± 0.3 nm) are well integrated with nanosized MXene (5.4 ± 0.2 nm), achieving superior catalytic efficiencies of 99.5% for 4‐NP, 98.4% for 4‐NA, and 84.5% for 4‐NB within 1 to 2 min. The apparent rate constants ( k _app ) and turnover frequency (TOF) values reached 1.457 min ⁻¹ and 73 h ⁻¹ for 4‐NP, 1.668 min ⁻¹ and 145 h ⁻¹ for 4‐NA, and 1.137 min ⁻¹ and 124 h ⁻¹ for 4‐NB, respectively. The nanocatalysts maintained excellent efficiency and stability over multiple recycling cycles. This study highlights the synergistic role of MXene‐noble metal interactions in achieving efficient and sustainable catalytic reduction for environmental and industrial applications.